Lisa Dekster

Abrasive Waterjet (AWJ) milling effectively processes high-strength materials like WNiFe tungsten alloy without altering their properties. This study investigates the effects of jet pressure, traverse speed, and abrasive mass flow rate on the machining performance. The results indicate that...

Non-conventional machining processes offer significant advantages over conventional ones, especially in terms of the productivity, cost, and surface integrity of the produced parts due to their higher flexibility. Abrasive waterjet machining, in particular, constitutes an ecologically friendly process with a negligible thermal impact on a workpiece, and it has considerable capabilities for obtaining the desired outcome by regulating some of its numerous parameters. Among these parameters, the abrasive type is particularly important due to its hardness, mesh size, and shape, which lead to considerable deviations on the obtained depth, kerf characteristics, and productivity. Thus, in this work, a comprehensive comparison is conducted on the use of garnet and silicon carbide particles for the slot milling of the Ti-6Al-4V alloy under different conditions. The capabilities of both abrasive materials are evaluated by statistical analysis regarding the depth of penetration, kerf width, kerf taper angle, and material removal rate (MRR), which are obtained under the same process conditions. Finally, a multi-objective optimization based on grey relational analysis (GRA) is performed for several different practical cases. It was found that, although silicon carbide is more efficient in optimizing individual process outputs, the use of a garnet abrasive can lead to considerably better trade-offs between two or more objectives of the machining process.

Non-conventional machining processes offer various advantages, including the capability of processing hard-to-cut materials with a reasonable cost and sufficient productivity. However, depending on the application, different machining strategies need to be employed, in order to increase the flexibility of the process and produce parts with a better quality. In this study, experimental work was conducted and the use of a multipass strategy during slot milling of titanium alloy with abrasive water jet milling (AWJM) was explored, by comparing the effect of different numbers of passes under different process conditions, such as the jet pressure and traverse feed rate. The performance was evaluated by means of the kerf characteristics, and the productivity through material removal rate (MRR) values. The results indicated that the use of a multipass strategy had a considerable impact on the kerf taper angle, apart from the depth of penetration; and although it leads to reduced MRR and cutting efficiency, choosing appropriate values of process parameters, such as a higher jet pressure and moderate traverse feed, in combination with a moderate amount of passes, can be beneficial for AWJM from different points of view.

During Abrasive Waterjet (AWJ) machining of hard-to-cut materials, apart from other important process parameters, the properties of the abrasive material can considerably influence the outcome. In this research, the efficiency of silicon carbide as an abrasive on the geometrical characteristics of the kerf is investigated. Slots were machined on a Ti-6Al-4V workpiece under various conditions and the Taguchi method was used to design the experiment. The findings indicate that SiC abrasives are effective for machining titanium alloys and the appropriate regulation of process parameters can considerably affect both the geometric characteristics of the kerf and productivity.